Apparatus for casting hollow ingots



Jan. 8, 1929.

H. LEMCKE APPARATUS FOR CASTING HOLLOW IGNOTS Filed Jan. 21, 1927 2 Sheets-Sheet 1 Jan. 8, 1929.

H. LEMCKE APPARTUS FOR CASTING HOLLOW IGNOTS 2 Sheets-Sheet 2 Filed Jan.

n Patented Jan. "8, 1929.

' UNITED lSTA-'rss PATENTy OFFICE.

HEINRICH LEMGKE, OF I-IILEN, GERMANY.

i APPARATUS FOR CASTING HOLLOW INGOTS.

Application filed January 21, 1927,Se1ia1 No. 162,559, and in Germany August 2, 1926.

My invention refers to the art of rolling tubes from malleable cast-iron andinore especially to the blanks, from which such tubes are rolled. It is an obliect of my 1nvention to provide a new kind of blank and also the means for producing same, whereby rolled tubes of this kind can be produred in a. cheaper and more eiir-,ient manner tha was hitherto possible.

In endeavouring to avoid the costly and di'licnlt punching of solid blocks of malleable, iron. when producing blanks to he rolled out into (tubes. it has been suggested to produce such blanks by casting. the cast-iron obtained from tli \.'Bessei11er converter. the

Siemens-Martin furnace or the electrical f urnace. being re-melted and hollow ingots being obtained by casting lthis re-molten metal.

It has further been snmrested to produce.l

o J0 such blanks b v centrifugal casting. l

'..M-cording to the present inventioni I avoid the re-melting by directly casting the malleable iron obtained in the Bessemer converter", the Siemens-Martin furnace, the J5 electrical furnace and the like from raw iron into the shape of hollow blanks adapted to be rolled out into tubes, making use of suitable cores which can be utilized in a greater number of succeeding operations.

In thus casting the blanks direct from the melting oven, I obtain hollow substantially cylindrical ingots, consisting of raw malleable cast-iron, which can be rolled out directly into tubes. In carrying out this process, I prefer using a plurality of juxtaposed casting moulds, a core extending axially into each mould, and I provide means for simultaneously filling all the moulds and for simultaneously 4f) withdrawing the cores from all the moulds, when the cast metal has Ysolidified in the moulds.

In the drawings affixed to this specitication and forming part thereof two modifications of a device yembodying my invention are illustrated diagrammatically by way of example. In the drawings, Fig. 1 is an elevation, partly in vertical section, and

Fig. 2 is a tion, while Fig. 3 is a view, similar to Fig. 1, of a second modification. Referring first to Figs. l and 2, 1, 1 are plan view of a first modifica- .eighlt cylindrical moulds mounted in two groups of four on a common supporting structure. 2. made of iron or some other suitable material, which extend axially through said moulds and through openings provided in the supporting structure, theprojecting bottom ends of the cores being all fixed in a bridge piece 4 which is suspended from two plungers 5 by means of rods 5. The plungers are surrounded by cylinders vmounted on lateral extensions of the supporting structure 2. A centrally disposed hopper 7 serves for lling the moulds with cast metal by way of suitable conduits 8 formed by hollow bricks 19, the .filling of the mouldsbeing effected from below as shown in dotted lines in Fig. 1. As soon as the cast .metal has solidified and cooled down sufficiently in the moulds, water under pressure is introduced through the openings 9 into the cylinders 6, whereby the plungers 5 and plunger rods 5 are forced downwards, carrying with them the bridge piece 4 and the cores 3 connected to it by nuts 10. In order to facilitate the withdrawal of the cores from thecastings, the cores have a conical form. As shown in Fig. 1 I prefer providing the cores with means for cooling them, the cores being made hollow and a water pipe extending into each core. The cooling water introduced through this pipe can escape through an opening in the cap 13 forming the bot-tom closure of the core. Preferably the water is introduced only after the cast metal has cooled down sufficiently to allow the core to be removed. The heat of the fiuid material` having caused the core to 3, 3 are conical hollow cores" expand, the cooling action of the water will cause a contract-ion of the core whereby it can be withdrawn from the casting with comparative ease.

The moulds 1 are then lifted off the casting by suitable mechanical -means and the hollow blanks 11 are now ready to be removed to the rolling mill.

While in the modification shown'in Fig. 1 the cores are shown as being introduced into the moulds' from below, Fig. 3 shows a modification in which the cores are introduced into the moulds from above. I-Iere the cores 3 are suspended from a top bridge piece 14 carried by plunger-s 15 surrounded by hydraulic cylinders 16, into which water under pressure can be forced by way of the bottom opening 17. In order to prevent the moulds 1 from being lifted also, they must/be firmly connected with the supporting structure 18. In this modification as well as in the one shown in Fig. 1 hollow cores may be provided with meansfor water liiting means here shown can also be replaced by mechanically or -electrically operated means.

In order to facilitate the withdrawal of the cores, an insulating coating may be arrangced on the surface of the cores, such coating consistinor for instance of graphite, clay, a mixture of, graphite, oil and sand or the like and being renewed after each casting operation.

.I solid cores are employed, I prefer makingthem of cast-iron, while the hollow cores are made of steel;

The withdrawal of the cores can further' be facilitated by using cores in twoparts divided along their axes.

The'hollow bricks'19 as well as the casting hopper 7, which also consists of such bricks, must be replaced by fresh ones after each casting.v The bricks are broken to pieces and the cast material contained therein is used as scrap.v

YI wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modications will occur tol a person skilled in the art.

I claim:-

1. Device for. casting hollow ingots comprising a supporting structure, a plurality of casting moulds mounted on said structure, a core extending axially into each mould and spaced from its inner walls, a bridge piece extending substantially in parallel'to said structure and havinr all said cores fixed to it, a pair of hydraulic plungers fixed to said bridge piece, one at each end, and a hydraulic cylinder at each end of said structure enclosing each plunger.

2. Device for casting hollow ingots comprising a supporting structure, a' plurality of casting moulds mounted on lsaid strucv ture, a core extending axially into each mould and spaced from its inner walls, a bridge piece extending substantially in par# allel to said structure and havinor all said cores fixed to it, a pair of hydraulic plungers fixed to said bridge piece, one at each end, a hydraulic cylinder at each end of said structure enclosing each plunger and common lneans for simultaneously pouring metal in all said moulds.

In testimony whereof I afix my signature.

HEINRICH LEMCKE, 

